Once Sinclair had sorted out the production problems, the machine as sold met the specifications set by Sinclair.

Sinclair only did research into the intended market after producing this computer!
It was launched well before it was ready for mass production. So buyers had to wait a lot longer than the specified 28 days to get the machine they had already paid for.
Due to the microdrives, and the dongle (fitted to the first batch of machines), the machines did not receive favourable reviews in the computer magazines and press.
The keyboard could have been better.
The dual RS232 ports are partly crippled.
The RS232 and the joystick ports use non-standard connectors.
A special monitor was needed (you could not get the full width display on a standard monitor).
Software manufacturers/suppliers hated the microdrive cartridges, they were hard and expensive to mass duplicate.

Once you get beyond these problems, the QL was a good machine.

By beyond, I mean when fitted with a third party disk drive system, a third party keyboard and a monitor/display that works with the QL.